


I Get Chills When You're Not Inside Me

by DroppedAllTheseOreos



Category: Kamen Rider Ex-Aid
Genre: Alternate Universe - Canon Divergence, Alternate Universe - Everyone Lives/Nobody Dies, Cis Kagami Hiiro, Cis Momose Saki, Dorks in Love, F/M, Fluff and Smut, It's minor but Saki awakens it in Hiiro, Kink Negotiation, Pegging, Size Kink, Sort of Exophilia, Strap-Ons
Language: English
Status: Completed
Published: 2020-09-11
Updated: 2020-09-11
Packaged: 2021-03-06 17:20:57
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,496
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26372608
Author URL: https://archiveofourown.org/users/DroppedAllTheseOreos/pseuds/DroppedAllTheseOreos
Summary: Now that Saki's back and Hiiro's had time to adjust to a new, healthier normal with her, they feel ready to start taking their relationship to the next level. The only roadblock is Hiiro finding it difficult to perform the way he thinks he's expected to. Fortunately for them, Saki's creative.
Relationships: Kagami Hiiro/Momose Saki
Comments: 8
Kudos: 6
Collections: Oreos' Fanfic Gauntlets





	I Get Chills When You're Not Inside Me

**Author's Note:**

> Title is lyrics from Rich Brian's "Love in My Pocket"

Unlike most of the other Riders who were still having trouble settling back into normalcy with the Bugster Crisis over, Hiiro was doing surprisingly well. He hypothesized that it had to do with how he was living before the outbreak. Yes, he did live with a vague knowledge of the virus and a huge chip on his shoulder for the past six years, but otherwise, he was allowed to live the most ordinary life out of any of them in between Zero Day to today.

Saki being back and having the others to support him helped a lot, as well.

At first, it was difficult. But eventually, he found his way. Saki was understandably confused and stressed when she was restored, but with some time and major readjustments, she was able to get back on her feet and return to a sense of being okay. Between Graphite, Kujo, and Poppy’s assistance (Hiiro was a bit leery of Parad being around her back then) she was able to come to terms with her sudden transition from human to bugster much more smoothly than she would've on her own. Hiiro still remembered the chaos from her first ever teleportation where she broke down and disappeared, disrupting most of the electronics in CR when she first learned what she was. Fortunately, Graphite seemed to have a similar kind of human-bugster bond to Saki that Hojo and Parad did, and he was able to find her and talk her through the event.

Of course, getting to where they were now, with Saki on the cusp of finishing her residency and Hiiro doing better than ever before now that he was going to therapy and his life wasn't constantly on the edge of crumbling, wasn't easy. It was a lot of difficult feelings and conversations to work through and Hiiro made sure to cherish every good moment they had.

And that's what he was doing right now, pressed up against the arm of the couch as he read through a light novel Nico had loaned Saki. Usually, he'd be going through medical news on his phone or books he hadn’t already gone through on the campus library; but, he'd finally hit a breakthrough in getting himself to let go of medical practice every once in a while. As much Hiiro he genuinely cared about doing surgery and learning everything he could, it was nice to use his free time to pick up some hobbies. He asked Saki if she wanted to read with him when she came home, but she shook her head, promising to show him a surprise after she ate something and showered.

He heard the water shut off and some shuffling around in the downstairs bathroom, and the corners of his mouth turned up in a slight smile. He tried to keep reading like nothing was happening, but found himself staring blankly at the page, wondering what she was up to. Before long, Hiiro felt something rest on his shoulder, too light to be a hand, but too heavy to be a bug or something else he'd want to immediately swipe at. Moments later, just like he suspected, a pitched-down "Hey," in Saki's voice followed the touch.

He sighed fondly and turned to see what she placed on him—immediately jolting back when he came face to face with an emerald green dildo. Hiiro shuffled backward to get a better look at it and saw that it was strangely textured and had some... extra parts that he wasn't exactly sure about, but the overall shape of it was definitely phallic, so any hopes he might've had that he just saw it wrong and it wasn't a dildo were immediately dashed. Saki laughed at his reaction and dropped her nightshirt so it bunched around the base of the phallic piece of silicone.

Hiiro was now keenly aware of how his face was burning and one of his hands came up to press against it, instinctively trying to hide.

"Saki... Why does it look like you have… something of Graphite’s attached to you?"

Her face immediately lit up with excitement at that, "Oh? Hiiro are you implying that you and his relationship might've been closer than you actually said at first?"

"No!" Hiiro yelled, his other hand came up to cover his face, "It just looks like something that would be attached to him because of the color and all the… _stuff_ on it!”

She let out a full-bodied laugh at that point, doubling over as Hiiro hid his face further. When her laughter died down, leaving only the beaming grin on her face, she moved to sit next to him on the couch. She waited for Hiiro to finally feel comfortable enough to put his hands down before she opened her mouth again.

“Well actually, Graphite told me he doesn’t have a knot. But, if you’re ever curious you could ask Taiga or Kiriya for details.”

Hiiro spluttered again, and Saki spared him the embarrassment of cackling at him, just keeping it down to a little snicker and patting his shoulder comfortingly.

“How do you even know that—“ He caught himself and pouted slightly, looking away embarrassedly, “Right, your link… Wait does that mean they finally…?”

Saki nodded with a gleam in her eyes, “Let’s just say, Taiga’s about as awkward as we thought,” Hiiro shook his head exasperatedly as she started talking again, “Also, you were sort of right, though. Graphite helped me pick this thing out, and it was the closest thing I could find since Genm doesn’t have any officially licensed products yet.”

“Why would they—? And why were you looking—? He helped you pick it out?” Hiiro’s eyes darted between her and the dildo still poking out from under her shirt.

“Well, you know how it’s been a bit awkward every time we’ve tried to have sex right?” Saki’s jovial demeanor suddenly changed to something a little more serious.

Yes, Hiiro knew. He was all too familiar with how he wasn’t cut out for that part of their relationship. Until Saki tried shaking things up and put him under her instead. Sex had never been all that interesting to him, but the way she gently rode his face or pinned him against a wall to kiss and softly bite while she rolled her hips against him was electrifying. Hiiro quickly found his disinterest was just from the _way_ he thought about it before.

Being with Saki taught him it wasn’t just penetration. Sex could be soft touches and warm, wet lips, or hints of teeth, all seeking out where he felt good. Unlike other times he imagined it, Saki showed him a wonderful mix of assertive and gentle attention that never failed to get him off. And now that he experienced it, he could imagine melting under anyone he trusted enough to treat him that way. Not that he wanted to now, but having all these new avenues opened to how he thought about sex was comforting and liberating all at once.

“Well, I was thinking, ‘since Hiiro’s not all that comfortable being on top, why don’t I try?’ The selection of dick was because I saw the prices of some others and thought like, if I’m going to buy one, might as well go all out and find something I’d get a kick out of using” Her smile turned a bit nervous, “And, well, you know how I tend to just go for things when I get an idea in my head.”

Hiiro nodded, he was no stranger to her impulsiveness. They wouldn’t have met if she hadn’t just sat down across from him that first day, and he’d been witness to it many more times in college, and even after her return. He couldn’t help but smile fondly as he watched her nervously fumble with her hands and continue.

“So, if it’s too weird, I can just put this away and we can have a regular night in—”

Hiiro cut her off by jerkily leaning forward, but getting scared off at the last second by her flinch and wide eyes from his sudden movement. She laughed surprisedly and leaned in the rest of the way to meet him properly for the kiss. He smiled into it, they’d gotten pretty good at reading each other.

“I think I’d like to try it out, actually.” Hiiro said softly against her lips when they separated.

She leaned back with wonder glittering in her eyes and he had to chuckle a little, brushing his thumb over her knuckles to calm her down.

“Go upstairs and relax for a bit, I… uh. Need to get ready?”

“Yeah you do,” Saki kissed his temple, “I’ll see you soon, Hiiro.”

And with that she was heading up to his room, and he took a moment to soak in the whole experience, then headed into the bathroom to make sure certain areas of him were… suitably clean for the rest of the night.

* * *

About an hour later found the two of them in a familiar but different position. When they tried it before, it was Saki laying across the width of the bed, legs hanging off while Hiiro stood between them, trying to feel turned on. But tonight, every nerve in his body was alight with anticipation. They barely even started and he was already trembling. Saki started him face down for better access and to make sure her prep was thorough. Even though Hiiro had gotten more used to fingering himself when Saki showed him how good it could be, he’d never taken something as… well, big as the dildo she had strapped to herself.

“I bought the medium one to go easy on you this time,” Saki whispered while she was three fingers deep in him, and it made goosebumps prickle all over Hiiro’s skin.

That wasn’t even the biggest size? His brain was rushing with all the possibilities of what the bigger sizes would be like. And that whispered _‘this time’_ had him burning up inside from anticipation. He could barely even imagine how it would feel like but he relished the idea of being so full and the visuals that were coming to mind.

Hiiro’s train of thought got cut off when Saki flipped him over, his hole reflexively clenching down on the empty feeling while she maneuvered him into a better position. When he finally relaxed again, she started guiding the head to press lightly against his hole.

The next few minutes were blissful agony that stretched into hours in his mind. In the logical part of Hiiro’s brain, buried somewhere under all the arousal and sensation, he knew she was just trying not to hurt him. But every other part that was caught up in the heat of the moment had him whining and crying out for her unabashedly. The way she was opening him up, so slow and deliberate but wider than anything he’d ever taken before, was overwhelming him in the best possible way.

“Saki please, I can take it. I want to feel all of you already, please, please, please.”

She grabbed onto his thighs, squeezing them reassuringly, then pushed them up as far as they’d go. Her hands trailed up to his knees, guiding his legs to rest against her body as she leaned in to press a kiss on his chest.

“Don’t worry, I got you,” she murmured into his skin.

Hiiro felt a little bitter at the words of comfort when all she did was continue her slow, torturous slide into him. But when they finally came to the part he was eagerly anticipating, his feelings suddenly changed towards it. The second the knot bumped up against his hole he started to panic, realizing it absolutely wasn’t going to fit. Why was he so excited for a bigger version of this earlier, there was no way it could fit in _anyone_ it was so big and hard and—

He tensed when he felt Saki try to push it in, but she immediately started pulling back until she was about halfway out and he breathed out a tiny sigh of relief. She held him there for a moment, and just when he started squirming for something, anything, she started thrusting in and out with small movements that had him tossing his head back in relief. Eventually, she got bolder, and he loosened up, finally getting back to that feeling from the beginning where he was melting into the sheets and every nerve felt like it was tingling with pleasure. The overwhelming feeling from before was gone, and now he could really feel what it was like every time she pushed into him. He was certain that he could feel every ridge and scale and bump as they hit his insides in a way that sent jolts of pleasure shooting up his spine and through his nerves, settling into a low, tingling warmth in his fingers and toes.

“Hiiro?” Saki’s voice and her hand shaking the leg it was gripping took him out of his blissed-out state, making him feel like he just broke the surface after being deep underwater and he blinked up at her dazedly, “You doing okay? Still with me?”

He nodded as best he could, taking the opportunity of his sudden awareness to prop himself up on his elbows and look down to where she was currently buried deep inside him. When Saki’s hips pulled out, he felt a deep groan get lodged in his throat. The sight of the dildo thrusting in and out of him, practically dripping with lube and shining in the lamplight was making his stomach do all sorts of flips. Watching it slide in so easily, he could scarcely remember why he was so intimidated by it in the first place.

For a while, he was just mesmerized by the sight of their hips meeting over and over. Hiiro found himself getting turned on in a distant, floaty sort of way. Not exactly an out of body experience, but sometimes the pleasure he was feeling would disconnect from the visuals of himself getting fucked and became this dual sensation of the pleasure in his body and the arousal from watching “someone else” get fucked by a dragon dildo.

Hiiro had no idea how much time had passed since they started, but Saki pulling out all the way and taking a few steps back broke him out of his floaty state and he thrust his hips to try and meet hers, seeking out that full feeling again. Saki just chuckled low and let his legs drop back down to the mattress.

She was deceptively slight-looking with clothes on, but she was able to easily lift him and rearranged him as she liked on the bed so he was lying across it properly while she knelt between his legs, leaning forward on her hands momentarily to kiss him softly. He watched in dazed awe as she took her nightshirt off, tossing it to the floor to reveal lovely planes of skin that Hiiro found himself already reaching out to touch. She giggled a little as she lifted his hips to re-enter him, holding his hand to keep it pressed against her hip as he threw his head back to moan.

Saki tried to set a faster pace this time, but they had a few false starts for her to get them into a more comfortable position. When she finally found a position she liked, his knees over her shoulders again and his ass up to meet her hips at just the right angle, Hiiro was a writhing, moaning mess under her in minutes. Any traces of the cold, professional surgeon from when he was at work were completely gone here. Hiiro barely had enough room in his head to remember his name. Everything that normally worried him or took up his thoughts was almost completely pushed out by pleasure, and sensations and thoughts of Saki.

Soft skin under his hands. Little moles and patches of pale discoloration marking where she tanned unevenly led his eyes over the planes of her skin like landmarks. As he ran his hands over her, he was entranced by the way the marks and tones of her skin stretched and shifted with each move that she made, and his palms tingled with the feeling of her muscles just underneath.

The motion of her hair, curls and waves bouncing in the low lamplight like an inky ocean with every thrust inside him.

A sigh, a laugh, a pleased groan. He hung on every sound she let out and it fed the fire burning under his skin.

She squeezed the thigh in her hands, digging her nails in just a bit, not enough to hurt, but enough to make him flinch, his hole instinctively clamping down on the dick buried deep inside of him.

The thrusts grew quicker and he caught a flash of teeth, honing in on her lips to see her grinning. But trailing up to watch her eyes, he could see how focused she was and the determination on her face was… for lack of a better word, sexy. Something about the way she looked like she was enjoying herself, but also giving all her focus and attention to him fueled the fire in his belly and he could feel himself trembling.

“Do you wanna try taking it again?”

Hiiro’s eyes widened and a hoarse, “yes” tore from his throat.

Saki suddenly leaned forward, entwining their fingers as she thrust harder and harder into him until he was sobbing into her mouth and finally coming, semen splattering all over his belly. She pulled back a fraction, smiling and panting against his mouth as she shifted on her knees, and suddenly his hole was being stretched like never before, slowly widening into an overwhelming feeling until there was a sudden slide, the head of the cock hitting him deeply and Saki pressing against him even closer than before.

Hiiro was left gasping and writhing under her as his cock twitched and another trickle of cum bubbled out of him. Saki stayed there inside him, burying her face against his neck and covering it in kisses. When she was satisfied that she covered every centimeter of skin, she started moving up to his face, making him chuckle tiredly. She kept going until he started collapsing back into the mattress, putting her energy into cuddling him tight instead. Weakly, he reached up a hand and tangled it in her hair, twisting the locks around his fingers lazily. As they laid there together, Hiiro found himself coming back from whatever sort-of-not-really out of body experience he was in that whole time and he actively started nuzzling against Saki, making her giggle.

He pressed a soft kiss on her cheek, and she rolled him onto his back so she could pull the dildo out of him. He shuddered, letting out an appreciative, involuntary groan. Saki brushed her hand through his hair in a soothing motion then sat on the edge of the bed, getting the harness off her and set it on the nightstand for lack of a better place after fumbling around with it for a while.

When Saki came back to lie down with him, he took her in his arms, trailing one down her side and then tentatively placing his hand over the damp, burning space between her legs.

“Hiiro, you don’t have to…” She said, ducking her head and looking shy for the first time all night, “I already put you through a lot.”

He did his best to look earnest as he said, “I want to.”

She seemed to think about it for a while longer, then just smiled and nodded, pressing closer to him and grinding down against his hand briefly. He kissed her cheek and started by lightly tracing around her clit. It wasn’t too hard to find since she was already pretty turned on. He focused on making little semi-circles around the base, keeping his touch light until her hips started jerking back and forth. He started applying more pressure, speeding up his movements and trying to keep going in ways he knew she liked until she groaned against his chest where she tucked herself. Her leg started spasming and then her whole body shook, wracked with her orgasm until she went limp and rolled onto her back with a huge, content sigh.

Saki lay there, panting, with her eyes closed for a while, and he watched adoringly until he felt the need to roll onto his back and collapse as well. She let out another, softer this time, sigh and cracked one eye open to look at him.

“So, was this a good idea?”

Hiiro nodded, smiling softly at her; which grew into a grin as he saw her shocked reaction to his response:

“Make sure you buy the bigger one for next time.”


End file.
